Email sending fails with private email domain: C# code
public void sendEmailWithHotmail(string emailFrom, string emailPwd, string emailTo, string smtpHost, int smtpPort, string msg)
    {
        MailMessage mail = new MailMessage();
        mail.From = new MailAddress(emailFrom, "Test EMail");
        mail.To.Add(emailTo);
        mail.Subject = "Hi";
        mail.Body = msg;
        mail.Priority = MailPriority.Normal;

        NetworkCredential mailAuthentication = new NetworkCredential(emailFrom, emailPwd);
        SmtpClient mailClient = new SmtpClient(smtpHost, smtpPort);
        mailClient.EnableSsl = true;
        mailClient.UseDefaultCredentials = false;
        mailClient.Credentials = mailAuthentication;
        mailClient.Timeout = 20000;
        mailClient.Send(mail);
    }

Gmail   -> smtp port: smtp.gmail.com,   smtp Port: 587
Hotmail -> smtp port: smtp.live.com,   smtp Port: 25
Yahoo   -> smtp port: smtp.mail.yahoo.com,   smtp Port: 25

<system.net>
    <mailSettings>
      <smtp from="abc@somedomain.com">
        <network host="somesmtpserver" port="25" userName="name" password="pass" defaultCredentials="true" />
      </smtp>
    </mailSettings>
 </system.net>

msg.ReplyToList.Add(replyTo);